Oridonin is a shellene diterpenoid type of natural organic compound, which is separated from the plant Rabdosia rubescens (Labtea, Rabdosia) and is a main component of Herba Rabdosiae.
It has heat-cleaning and detoxicating effects, effects of promoting blood circulation and removing blood stasis, and anti-bacterial, anti-inflammatory and anti-tumor effects (ZHAO Yongxing et al. Preparation and in vitro anticancer effect of oridonin nanoparticles [J]. China Journal of Hospital Pharmacy, 2008, 28 (11): 864-867; L I U Chenjiang et al., Antitumor effect of oridonin [J]. China Pharmaceutical Journal, 1998, 33:577).
Scientists have conducted extensive research on oridonin and analogues thereof, including separation, purification, structural identification and modification, studies of biological activity in vivo and in vitro, in the hope of discovering novel medications with clinical applications (L I U Ke et al., Oridonin derivative and preparation thereof [P]. CN 101723951, 2010; L U Jinjian et al., Natural anticancer products separated from Chinese herbal medicine [J]. China Journal of Chinese Materia Medica, 2011, 6:27-27; ZHAO Ming et al. One single HPLC-PDA/(−)ESI-MS analysis to simultaneously determine 30 components of the aqueous extract of Rabdosia rubescens [J]. Journal of Chromatography B: Analytical Technologies in the Biomedical and Life Sciences, 2011, 879 (26): 2783-2793; ZHAO Peng et al. UPLC method for determination of oridonin content in Rabdosia plant [J]. Chinese Traditional Patent Medicine, 2011, 3 (3): 540-542; S U N Handong et al., Rabdosia plant diterpenoid compounds, Science Press, 2001; X U Jinyi et al., Oridonin derivative and preparation method thereof [P]. CN 101139350, 2008; X U Jinyi et al., Ent-6,7-open-cycle kaurene type rubescenesine A derivative with anti-tumor activity and preparation method and use thereof [P]. CN 102002051, 2011; X U Jinyi et al., Oridonin with antitumor resistance activity, fluorine-containing derivative of 6,7-open ring oridonin, preparation method and application thereof [P]. CN102295649, 2011).

Studies have found that oridonin has cytotoxic effect with a broad anti-tumor spectrum, including acute myeloid leukemia, chronic myelogenous leukemia, uterine cancer, breast cancer, lymphoma, osteosarcoma, gastric cancer, esophageal cancer, liver cancer, gallbladder cancer, nasopharyngeal carcinoma, lung cancer, melanoma, skin cancer etc. (L I U Jiayin et al., Progress in research of oridonin and antitumor activity [J]. China Journal of New Drugs and Clinical Remedies, 2010, 29 (2): 81-84).
Oridonin induces apoptosis of tumor cells through the control of mitochondrial apoptotic pathway and achieves the effect of blocking cell cycle and malignant growth mainly by controlling the following conversion pathways: p53, Ras/Raf/ERK, PI3K/Akt and NF-k13 (L I Chunyang et al., Oridonin: a diterpene having cancer treatment activity in blocking cell cycle, inducing cell apoptosis and autophagy [J]. International Journal of Biochemistry and Cell Biology, 2011, 43 (5): 701-704; L I Xiaojie et al., Oridonin regulates mitochondrial apoptosis by controlling signal conversion pathway [J]. Cancer Research and Clinic, 2010, 22 (4): 286-288).
The poor water solubility and low bioavailability of oridonin has limited its clinic applications. Researches have been done on the structural modification of oridonin with an eye to find a compound with better activities. The Fujita group of Japan has structurally modified the 14-position hydroxyl of oridonin and discovered that only the derivative acylated at 14-position with long-chain fatty acids has a biological activity significantly higher than that of oridonin itself (Fujita, Eiichi. Biologic and physiological activity.II Antitumor activity of acylated oridonin [J], Chemic & Pharmaceutical Bulletin, 1981, 29(11):3208-3213).
This field is in need of novel compounds with antitumor activity, particularly having improved antitumor activity.